javax.swing.text.BadLocationException: Invalid offset=-1 not within <0, 8800>
        at org.netbeans.editor.Utilities.checkOffsetValid(Utilities.java:1331)
        at org.netbeans.editor.Utilities.getLineOffset(Utilities.java:613)
        at org.netbeans.modules.html.editor.gsf.HtmlStructureScanner$1.visit(HtmlStructureScanner.java:120)
        at org.netbeans.editor.ext.html.parser.AstNodeUtils.visitChildren(AstNodeUtils.java:90)
        at org.netbeans.modules.html.editor.gsf.HtmlStructureScanner.folds(HtmlStructureScanner.java:135)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.addTree(GsfFoldManager.java:403)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.scan(GsfFoldManager.java:396)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.gsfFoldScan(GsfFoldManager.java:320)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.run(GsfFoldManager.java:287)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.run(GsfFoldManager.java:246)
        at org.netbeans.napi.gsfret.source.Source$CompilationJob.run(Source.java:1242)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)